1. Field of the Invention
The present invention relates to the enhancement of antimicrobial activity of a biodegradable or non-biodegradable suture used during surgery, and more particularly, to the enhancement of antimicrobial activity of a suture by functional materials included in a grapefruit extract having an antimicrobial effect by immersing the suture in a solution in which the grapefruit extract is dispersed.
2. Description of the Related Art
A suture is an important medical suturing material used such that the open parts of a surgical site are drawn together and located in position until the wound is healed up. Conditions required for the suture as a medical material include high biocompatibility, chemical stability, flexibility, durability, heat resistance, moldability, and processability, as well as low production cost.
Examples of such sutures include absorbable sutures and non-absorbable sutures. The absorbable sutures include natural sutures such as catgut and collagen, synthetic sutures such as PGA and PLA, and the non-absorbable sutures include polyester, nylon, etc.
The history of surgical sutures starts with a record that the Egyptians used tendons or strings as sutures in 3000 BC, and since then, through the Roman Era and the Middle Ages, a bioabsorbable suture was developed from goatskin and deerskin in 1806 for the first time by the University of Pennsylvania School of Medicine. Since then, synthetic sutures were developed and used about 50 years ago, and synthetic bioabsorbable sutures have recently been produced in various forms such as a hard clip, etc.
Meanwhile, catgut made of extracts from organs of animals such as cattle, sheep, etc. was widely used until the 1970s, but its use has gradually decreased due to low strength, which causes poor productivity, and due to tissue response, which causes side effects. Catgut originated from the use of intestines of cats and, since the 1970s, surgical sutures made from synthetic fibers, in which ester groups of polymer are hydrolyzed by body fluid in tissues and absorbed by themselves, have been steadily developed.
The synthetic sutures may be broadly classified into a polyglycolic acid (PGA) suture made by twisting several strands of thread and a polydioxanone (PDO) suture made of a single strand of thread. The PDO suture consists of a single strand of thread and thus has low flexibility and elasticity, but its surface is smooth and the risk of bacterial infection is low due to no space between threads. On the contrary, the PGA suture is made by twisting several strands of thread and thus has high flexibility and elasticity, but its surface is rough and the risk of bacterial infection is high due to the space created between the threads.
A poly(glycolide-co-L-lactide) (PGLA) suture developed to overcome the drawbacks of the above-mentioned two type of sutures is a copolymer, which is polymerized using glycolide and lactide as raw materials and thus has good flexibility and elasticity. Moreover, the roughness of its surface can be reduced by improving coating efficiency using calcium stearate as a coating material.
Moreover, the biodegradation period of the PGA and PLA homopolymers depends on the molecular weight, but is generally more than one year. However, the PGLA as a copolymer thereof is biodegraded over several weeks to months depending on the molecular weight.
Conditions required for the above various sutures are to have suitable tension and elasticity, to cause no reaction in the tissues, and to provide an environment where germs, bacteria, or viruses cannot grow.
Furthermore, the suture should not cause allergic and hypersensitive reactions or have no carcinogenicity, should be convenient to use, should prevent a knot or string from being easily untied or cut, should be easily cut after making the knot, and should prevent its form or composition from changing during autoclave sterilization. Meanwhile, since the reformation of scar is slowly made, the suture should have a certain amount of strength that is maintained for the period required for the induction of tissue.
As such, the biodegradable suture should be convenient to use and should reduce the occurrence of infection during surgery.
In order to solve the problem of the occurrence of secondary infections due to the suture, materials having an antimicrobial effect such as nano-silver particles have been conventionally used to impart antimicrobial activity to the sutures. However, when these nanoparticle materials are introduced into the body, they remain in the body for a long time, which is problematic.
Meanwhile, naringin as one of the components of the grapefruit extract is a type of flavonoid known as vitamin P having an antimicrobial effect, mainly present in the seed and peel of a ripe grapefruit, and tastes bitter. Its molecular formula is C27H32O142H2O and its chemical structure may be represented by the following chemical formula 1:

The main functions of the naringin are as follows. First, the naringin has a bacteriostatic effect to inhibit the growth of microorganisms in food and an antimicrobial effect to sterilize microorganisms. Moreover, the naringin has an antioxidative action and is a strong antioxidant that has a greater effect than fat-soluble tocopherol in food. In particular, the naringin is water-soluble and thus has a wide range of uses and is non-toxic even after excessive intake.
The principle of the antioxidative action of the naringin may be simply represented by the following chemical formula 2:

Moreover, the naringin has a metal chelating action to interfere with the enzymatic reaction in a cell membrane, thus inhibiting the growth of bacteria. In addition, the naringin has the potentiating effect of ascorbic acid to improve the stability of ascorbic acid in food. Furthermore, the naringin has the ability to inhibit the growth of malignant cells and an anticancer effect to restore cells damaged by carcinogens.
The present inventors have developed a suture and a manufacturing method thereof, which has an antimicrobial activity and prevents nanoparticles from remaining in the body by applying a grapefruit extract containing naringin with these various functions to the suture.